Microwave coaptive surgical sealing tool

ABSTRACT

A coaptive surgical sealing tool may be similar to an ordinary hemostat with long (50, 60, 70 or 80 mm) thin jaws for sliding into the liver parenchyma, without tearing the larger blood vessels. The jaws are spring loaded and are designed for uniform compression, and to avoid closing too quickly. The jaws are capable of sealing a 50, 60, 70 or 80 mm sealing length, in a single bite, although it can also seal shorter lengths as well. The tool can be used with existing ablative therapy microwave generators. The tool may be provided with irrigation and/or suction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a Continuation of U.S. patent application Ser. No.14/887,741 filed on Oct. 20, 2015, which is a Continuation of U.S.patent application Ser. No. 14/326,736 filed on Jul. 9, 2014, now U.S.Pat. No. 9,186,215, which is a Continuation-in-Part of U.S. patentapplication Ser. No. 13/928,204 filed on Jun. 26, 2013, now U.S. Pat.No. 9,173,707, which is a continuation-in-part of U.S. patentapplication Ser. No. 13/842,510 filed Mar. 15, 2013, now U.S. Pat. No.9,186,214, which claims priority to U.S. Provisional Patent ApplicationNo. 61/706,603, filed Sep. 27, 2012. Each of these applications isincorporated herein by reference.

BACKGROUND OF THE INVENTION

Removal of part of the liver (hepatic resection) is often performed toremove a tumor. Blood loss is a serious complication associated withthis procedure. Multiple surgical techniques and devices have beendeveloped to minimize blood loss and improve outcomes in hepaticresection. Several studies including a 2009 Cochrane Systematic Reviewof techniques for liver parenchymal transection have examined theefficacy of different methods of liver resection. Based on this review,the clamp-crush technique was favored due to low cost and with newertechniques such as cavitron ultrasound surgical aspirator (CUSA),hydrojet, and radio frequency dissecting sealer (RFDS) showing noimprovement in morbidity or blood transfusion in comparison to theclamp-crush technique.

The clamp-crush technique generally involves crushing the liverparenchyma using a hemostatic clamp tool to expose small vessels andbiliary radicals, which are then divided and sealed via radio frequency(RF) energy provided to the jaws of the tool. Various tools have beenproposed for this purpose. However, challenges remain in providing acoaptive surgical sealing tool offering superior performance andefficiency in a simple and low-cost design. It is an object of theinvention to provide an improved coaptive surgical sealing tool

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, the same element number indicates the same elementnumber in each of the views.

FIG. 1 is a perspective view of a coaptive surgical sealing tool.

FIG. 2 is a perspective view of another coaptive surgical sealing toolfurther including irrigation.

FIG. 3 is an enlarged partial section view design detail of an electrodepair that may be used on the jaws of the tool shown in FIG. 1 or 2.

FIG. 4 is an enlarged partial section view design detail of an insulatedtool arm providing an irrigation or suction line.

FIG. 5 is an enlarged partial section view alternative design detail ofan insulated tool arm providing an irrigation or suction line.

FIG. 6 is a perspective view of an alternative modification of the toolshown in FIG. 2 further including irrigation and suction.

FIG. 7 is a perspective view of another alternative tool design usingmicrowave energy.

FIG. 8 is an enlarged side view of the jaws of the tool shown in FIG. 7.

DETAILED DESCRIPTION OF THE DRAWINGS

A coaptive surgical sealing tool may be similar to an ordinary hemostatwith long (50, 60, 70 or 80 mm) thin jaws for sliding into the liverparenchyma, without tearing the larger blood vessels. The jaws, arespring loaded and are designed for uniform compression, and to avoidclosing too quickly. The jaws are capable of sealing a 50, 60, 70 or 80mm sealing length, in a single bite, although it can also seal shorterlengths as well. The tool can be used with existing RF/bi-polar cauterygenerators, including generators the Triad- Covidean Ligasure Generator,the ConMed generator or the Enseal generator. The tool is suitable foropen surgery uses, and may also be adapted for laparoscopic surgery. Thetool may be provided in different sizes for different caliber ofvessels. In view of its simple design, the tool may be supplied at lowcost, as either a reusable or single use unit.

In use, the jaws may be closed with a gradual compression process, witha compression spring acting against the closing movement, to preventtearing of larger blood vessels. The jaws may a slot and/or ridge, toleave a pre-grooved line for transection after the seal has beencompleted. The tool may reduce parenchymal transection times in excessof 50%. With 55 mm or more of sealing length it can seal more tissue inone bite than any existing device yet it is also versatile enough toseal small lengths of tissue.

As shown in FIG. 1, an example of the tool 10 has first and second arms12 and 14 pivotally connected via a hinge 16. A finger ring 18 isprovided on the back or proximal end of each arm 12, 14. Each arm 12, 14has a jaw 24 in front or distal of the hinge 16. A spring 26 urges thejaws into an open position. A lock tab 20 may be provided adjacent toeach finger ring 18, to allow the jaws 24 to remain clamped or closed,against the force of the spring. The tool 10 according is similar to ahemostat clamp, and consequently benefits from ergonomic design elementsof a hemostat clamp. Hence the tool 10 provides ease of use when used inopen surgery. Connectors 22 may connect electrodes 30 on the jaws 24 toan RF generator.

The jaws 24 are very thin and easy to slide through the liver parenchymawithout disrupting the parenchyma architecture. For example, the jawsmay a length AA or 50, 60, 70 or 80 mm, and a width BB of 4, 5, 6 or 7mm. The spring 26 helps to prevent accidentally closing down on theparenchyma to quickly which prevents parenchymal disruption. The jaws 24may be straight or curved with a radius R of about 3-10 cm. Typically,the curvature of the jaws, if any, is in the downward direction, i.e.,about an axis parallel to the axis of the hinge 16.

The electrodes 30 may extend over the full length of each jaw 24, oronly partially over each jaw 24, as shown in FIG. 1. The electrodes 30may optionally be removable and separately replaceable.

A low cost embodiment of the tool may be provided by modifying aconventional hemostat clamp having long slender jaws, to include thespring 26, the electrodes 30 and connectors 22.

As used for hepatic resection, the surgeon slides the jaws 24 throughthe liver parenchyma. With the jaws appropriately positioned around avessel or biliary radical, the jaws 24 are slowly closed via the surgeonsqueezing the finger rings 18 towards each other. The electrodes 30 onthe inside of the jaws are clamped or pressed onto opposite sides of thevessel. The spring 26 acts against this closing movement, helping toprovide a slow and controlled movement. With the tool 10 heldmomentarily in a fixed position, RF energy is then provided to theelectrodes 30, sealing the vessel.

The tool may of course also be used for other surgical procedures onother organs apart from the liver.

From 2010-2012, a total of 51 patients underwent >30% liver resectionfor malignant disease. All patients underwent open laparotomy forhepatic resection. The patient sample was diverse. The majority ofpatients underwent resection for metastatic disease to the liver; 4gallbladder cancer with radical liver resection; 1 hepatocellularcarcinoma; 3 patients had documented cirrhosis. Procedures included: 7patients were combined colorectal primary and liver resection; 2patients underwent second resection for recurrence; 7 patients hadadditional nanoknife procedures at the time of resection. Post-opadverse events within 30 days of surgery included 0 bile leaks; 1 bloodtransfusion; 1 return to operating room for colon anastomatic leak; nointra-abdominal abscess. Use of the present tool as described appears tobe a safe and effective technique for major hepatic resection withminimal post-operative adverse events.

During use of a bipolar surgical cautery tool, heat generated by thetool tends to result in char forming on the jaws. Char causes the jawsto stick to the tissue being cauterized, making the surgery moredifficult. Char also increases the electrical resistance between thejaws, reducing the cautery effect of the tool. Char can be reduced bysupplying an irrigation fluid to the cautery site, reducing the need forfrequently stopping the procedure to clean char from the jaws.

As shown in FIG. 2, a bipolar surgical cautery tool 50 may be similar tothe tool 10 shown in FIG. 1 and further include irrigation to reducechar. Irrigation may be provided via an irrigation port or fitting 52adapted for connection to a source of irrigation fluid, such as saline.The irrigation port 52 is connected to an irrigation line 54 on or inthe tool leading to the electrode 56. The irrigation line 54 may simplyhave a single outlet at the electrode 56, or it may have multipleoutlets 58 spaced apart along the electrode. The irrigation line 54 maybe provided as a flexible tube attached to the tool 50. Alternativelythe irrigation line 54 may be provided as an internal duct leading fromthe arm 12 to the electrode 56.

As shown in FIG. 4, in another design, one or both arms 12 mayoptionally be covered or coated with an insulating material 66, such asplastic or rubber, with the irrigation line 54 formed in insulatingmaterial 66. The insulating material may also optionally cover one orboth finger rings 18. As shown in FIG. 5, if the insulating material 66is used, the irrigation line 54 may alternatively be provided as an openflow space between the arm 12 and the insulating material 66.

In use, the source of irrigation fluid connected to the irrigation port52 may be linked to the RF generator switch so that irrigation fluidflows onto or out of the electrode 56 whenever the switch is on. Byapplying a constant drip or flow of, irrigation liquid during cautery,char build up is reduced.

FIG. 3 shows a modification of the jaw 24 where a projection 62 isprovided on the electrode 30 on the upper jaw and a complementary groove60 is provided on the electrode 30 on the lower jaw. The projection mayextend parallel to the longitudinal axis of the arm 24 and typically hasa height of 1-3 mm. Consequently, as the upper and lower jaws arebrought together, while the electrodes are cauterizing tissue, they alsoform a pre-grooved line in the tissue for transection, after the sealhas been completed.

Turning to FIG. 6, a tool 70 may be provided with the same design as thetool 50 shown in FIG. 2, further including suction for helping to removeexcess blood and/or irrigation fluid. The tool 70 includes a port orfitting 72 for attachment to a suction source. One or more suctioninlets 74 may be provided on one or both electrodes 30 or 58, with thesuction inlets 74 connected to a suction line 76 connecting to thesuction port 72. The suction line 76 may be designed in the same ways asthe irrigation line 54 described above.

Referring to FIGS. 7 and 8, a microwave coaptive vessel sealing tool 80has long tissue and vessel sealing jaws 82. An alternate energy formi.e., microwave energy may be applied to the jaws from the microwavegenerator 90, rather than using radio frequency energy, direct current,ultrasound, or other form of energy. Each jaw 82, or an electrode oneach jaw, is connected to a surgical microwave generator, e.g., of thetype currently used for ablative therapies. The microwave coaptivevessel sealing tool 80 is designed for sustained uniform compressionwithout shearing through the tissue. Gradual pressure may be appliedalong the jaws resulting in a very good seal of the tissue.

The microwave coaptive vessel sealing tool 80 may be designed to worklike an ordinary hemostat. The closure may be a gradual compressionprocess, protected by a spring or flexure resistance element 84 loadedmechanism to prevent tearing of larger blood vessels. The spring 84 maybe mounted on or at the pivot connection 86 attaching the jaws to eachother. The jaws may be extremely thin (as thin as the existing needles),for example 1, 2 or 3 mm wide, to allow for sliding it in to the liverparenchyma without tearing any of the vessels or tissues. The toolsdescribed above with reference to FIGS. 1-6 may also optionally beconnected to a microwave generator 90 instead of an RF energy source.

The tool 80 may be provided with an insulated covering with an optionalinbuilt irrigation channel. If used, the irrigation channel may providea steady drip of saline when the microwave switch is activated, to helpto prevent the tissue from getting charred and keeping the jaws of thetool 80 clean. Using the tool may leave a pre-grooved line fortransection after the seal has been completed. The tool may be capableof reducing parenchymal transection times in excess of 50%. With 55 mmof sealing length, the tool 80 may seal more tissue in one bite thanexisting devices, while still being versatile enough to seal smalllengths of tissue. The tool 80 may be inexpensive to allow it to be usedwith existing microwave generators.

Thus, novel designs and methods have been shown and described. Variouschanges and substitutions may of course be made without departing fromthe spirit and scope of the invention. The invention, therefore, shouldnot be limited, except by the following claims and their equivalents.

1-11. (canceled)
 12. A surgical tool comprising: first and second arms,each having a front section and a back section, and with the armspivotally attached to each other at a pivot connection between the firstand second arms; first and second jaws on the front section of the firstand second arms, respectively, a biasing element coupled to the firstand second arms such that the biasing element biases the arms away fromeach other; first and second electrodes coupled to the first and secondjaws, respectively; a microwave generator coupled via a cable to thefirst and second electrodes; one or more irrigation fluid outlets in oradjacent to one or both of the first or second electrode; and a switchconfigured to apply microwave energy from the microwave generator and tosupply irrigation fluid through the one or more irrigation fluid outletswhen the switch is activated.
 13. The surgical tool of claim 12, whereinthe first and second jaws each have a width of 3-7 mm, a length of 5 to9 cm, and a finger ring on the back section of each arm.
 14. Thesurgical tool of claim 12, wherein the first and second jaws each have awidth of 4-6 mm.
 15. The surgical tool of claim 12, further comprisingfirst and second connectors electrically connected to the first andsecond electrodes and adapted to connect to the microwave generator. 16.The surgical tool of claim 12, further including a suction port on thefirst arm or the second arm and connected to a suction line leading toone or more suction openings in or adjacent to the first or secondelectrode.
 17. The surgical tool of claim 12, further including alongitudinal projection on the first electrode and a complementarygroove on the second electrode.
 18. The surgical tool of claim 12,wherein the one or more irrigation fluid outlets are connected to anirrigation port on the first arm via an irrigation line.
 19. Thesurgical tool of claim 18, wherein the switch is connected to themicrowave generator and to a source of irrigation fluid connected to theirrigation port.
 20. The surgical tool of claim 18, wherein theirrigation line comprises a flexible tube attached to the tool.
 21. Thesurgical tool of claim 18, wherein the irrigation line comprises aninternal duct leading from the first arm to the first electrode.
 22. Thesurgical tool of claim 18, wherein the irrigation line is attached toand extends along an outer surface of the first arm.
 23. The surgicaltool of claim 18, wherein the irrigation line extends within aninsulating material.
 24. The surgical tool of claim 12, wherein thebiasing element is a spring.